net/ieee802154/6lowpan.c

   1 /*
   2  * Copyright 2011, Siemens AG
   3  * written by Alexander Smirnov <alex.bluesman.smirnov@gmail.com>
   4  */
   5
   6 /*
   7  * Based on patches from Jon Smirl <jonsmirl@gmail.com>
   8  * Copyright (c) 2011 Jon Smirl <jonsmirl@gmail.com>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License version 2
  12  * as published by the Free Software Foundation.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License along
  20  * with this program; if not, write to the Free Software Foundation, Inc.,
  21  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  22  */
  23
  24 /* Jon's code is based on 6lowpan implementation for Contiki which is:
  25  * Copyright (c) 2008, Swedish Institute of Computer Science.
  26  * All rights reserved.
  27  *
  28  * Redistribution and use in source and binary forms, with or without
  29  * modification, are permitted provided that the following conditions
  30  * are met:
  31  * 1. Redistributions of source code must retain the above copyright
  32  *    notice, this list of conditions and the following disclaimer.
  33  * 2. Redistributions in binary form must reproduce the above copyright
  34  *    notice, this list of conditions and the following disclaimer in the
  35  *    documentation and/or other materials provided with the distribution.
  36  * 3. Neither the name of the Institute nor the names of its contributors
  37  *    may be used to endorse or promote products derived from this software
  38  *    without specific prior written permission.
  39  *
  40  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  41  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  42  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  43  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  44  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  45  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  46  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  48  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  49  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  50  * SUCH DAMAGE.
  51  */
  52
  53 #include <linux/bitops.h>
  54 #include <linux/if_arp.h>
  55 #include <linux/module.h>
  56 #include <linux/moduleparam.h>
  57 #include <linux/netdevice.h>
  58 #include <net/af_ieee802154.h>
  59 #include <net/ieee802154.h>
  60 #include <net/ieee802154_netdev.h>
  61 #include <net/ipv6.h>
  62
  63 #include "6lowpan.h"
  64
  65 static LIST_HEAD(lowpan_devices);
  66
  67 /* private device info */
  68 struct lowpan_dev_info {
  69         struct net_device       *real_dev; /* real WPAN device ptr */
  70         struct mutex            dev_list_mtx; /* mutex for list ops */
  71         unsigned short          fragment_tag;
  72 };
  73
  74 struct lowpan_dev_record {
  75         struct net_device *ldev;
  76         struct list_head list;
  77 };
  78
  79 struct lowpan_fragment {
  80         struct sk_buff          *skb;           /* skb to be assembled */
  81         u16                     length;         /* length to be assemled */
  82         u32                     bytes_rcv;      /* bytes received */
  83         u16                     tag;            /* current fragment tag */
  84         struct timer_list       timer;          /* assembling timer */
  85         struct list_head        list;           /* fragments list */
  86 };
  87
  88 static LIST_HEAD(lowpan_fragments);
  89 static DEFINE_SPINLOCK(flist_lock);
  90
  91 static inline struct
  92 lowpan_dev_info *lowpan_dev_info(const struct net_device *dev)
  93 {
  94         return netdev_priv(dev);
  95 }
  96
  97 static inline void lowpan_address_flip(u8 *src, u8 *dest)
  98 {
  99         int i;
 100         for (i = 0; i < IEEE802154_ADDR_LEN; i++)
 101                 (dest)[IEEE802154_ADDR_LEN - i - 1] = (src)[i];
 102 }
 103
 104 static int lowpan_header_create(struct sk_buff *skb,
 105                            struct net_device *dev,
 106                            unsigned short type, const void *_daddr,
 107                            const void *_saddr, unsigned int len)
 108 {
 109         struct ipv6hdr *hdr;
 110         const u8 *saddr = _saddr;
 111         const u8 *daddr = _daddr;
 112         struct ieee802154_addr sa, da;
 113
 114         /* TODO:
 115          * if this package isn't ipv6 one, where should it be routed?
 116          */
 117         if (type != ETH_P_IPV6)
 118                 return 0;
 119
 120         hdr = ipv6_hdr(skb);
 121
 122         if (!saddr)
 123                 saddr = dev->dev_addr;
 124
 125         raw_dump_inline(__func__, "saddr", (unsigned char *)saddr, 8);
 126         raw_dump_inline(__func__, "daddr", (unsigned char *)daddr, 8);
 127
 128         lowpan_header_compress(skb, dev, type, daddr, saddr, len);
 129
 130         /*
 131          * NOTE1: I'm still unsure about the fact that compression and WPAN
 132          * header are created here and not later in the xmit. So wait for
 133          * an opinion of net maintainers.
 134          */
 135         /*
 136          * NOTE2: to be absolutely correct, we must derive PANid information
 137          * from MAC subif of the 'dev' and 'real_dev' network devices, but
 138          * this isn't implemented in mainline yet, so currently we assign 0xff
 139          */
 140         mac_cb(skb)->flags = IEEE802154_FC_TYPE_DATA;
 141         mac_cb(skb)->seq = ieee802154_mlme_ops(dev)->get_dsn(dev);
 142
 143         /* prepare wpan address data */
 144         sa.addr_type = IEEE802154_ADDR_LONG;
 145         sa.pan_id = ieee802154_mlme_ops(dev)->get_pan_id(dev);
 146
 147         memcpy(&(sa.hwaddr), saddr, 8);
 148         /* intra-PAN communications */
 149         da.pan_id = ieee802154_mlme_ops(dev)->get_pan_id(dev);
 150
 151         /*
 152          * if the destination address is the broadcast address, use the
 153          * corresponding short address
 154          */
 155         if (lowpan_is_addr_broadcast(daddr)) {
 156                 da.addr_type = IEEE802154_ADDR_SHORT;
 157                 da.short_addr = IEEE802154_ADDR_BROADCAST;
 158         } else {
 159                 da.addr_type = IEEE802154_ADDR_LONG;
 160                 memcpy(&(da.hwaddr), daddr, IEEE802154_ADDR_LEN);
 161
 162                 /* request acknowledgment */
 163                 mac_cb(skb)->flags |= MAC_CB_FLAG_ACKREQ;
 164         }
 165
 166         return dev_hard_header(skb, lowpan_dev_info(dev)->real_dev,
 167                         type, (void *)&da, (void *)&sa, skb->len);
 168 }
 169
 170 static int lowpan_give_skb_to_devices(struct sk_buff *skb,
 171                                         struct net_device *dev)
 172 {
 173         struct lowpan_dev_record *entry;
 174         struct sk_buff *skb_cp;
 175         int stat = NET_RX_SUCCESS;
 176
 177         rcu_read_lock();
 178         list_for_each_entry_rcu(entry, &lowpan_devices, list)
 179                 if (lowpan_dev_info(entry->ldev)->real_dev == skb->dev) {
 180                         skb_cp = skb_copy(skb, GFP_ATOMIC);
 181                         if (!skb_cp) {
 182                                 stat = -ENOMEM;
 183                                 break;
 184                         }
 185
 186                         skb_cp->dev = entry->ldev;
 187                         stat = netif_rx(skb_cp);
 188                 }
 189         rcu_read_unlock();
 190
 191         return stat;
 192 }
 193
 194 static void lowpan_fragment_timer_expired(unsigned long entry_addr)
 195 {
 196         struct lowpan_fragment *entry = (struct lowpan_fragment *)entry_addr;
 197
 198         pr_debug("timer expired for frame with tag %d\n", entry->tag);
 199
 200         list_del(&entry->list);
 201         dev_kfree_skb(entry->skb);
 202         kfree(entry);
 203 }
 204
 205 static struct lowpan_fragment *
 206 lowpan_alloc_new_frame(struct sk_buff *skb, u16 len, u16 tag)
 207 {
 208         struct lowpan_fragment *frame;
 209
 210         frame = kzalloc(sizeof(struct lowpan_fragment),
 211                         GFP_ATOMIC);
 212         if (!frame)
 213                 goto frame_err;
 214
 215         INIT_LIST_HEAD(&frame->list);
 216
 217         frame->length = len;
 218         frame->tag = tag;
 219
 220         /* allocate buffer for frame assembling */
 221         frame->skb = netdev_alloc_skb_ip_align(skb->dev, frame->length +
 222                                                sizeof(struct ipv6hdr));
 223
 224         if (!frame->skb)
 225                 goto skb_err;
 226
 227         frame->skb->priority = skb->priority;
 228
 229         /* reserve headroom for uncompressed ipv6 header */
 230         skb_reserve(frame->skb, sizeof(struct ipv6hdr));
 231         skb_put(frame->skb, frame->length);
 232
 233         /* copy the first control block to keep a
 234          * trace of the link-layer addresses in case
 235          * of a link-local compressed address
 236          */
 237         memcpy(frame->skb->cb, skb->cb, sizeof(skb->cb));
 238
 239         init_timer(&frame->timer);
 240         /* time out is the same as for ipv6 - 60 sec */
 241         frame->timer.expires = jiffies + LOWPAN_FRAG_TIMEOUT;
 242         frame->timer.data = (unsigned long)frame;
 243         frame->timer.function = lowpan_fragment_timer_expired;
 244
 245         add_timer(&frame->timer);
 246
 247         list_add_tail(&frame->list, &lowpan_fragments);
 248
 249         return frame;
 250
 251 skb_err:
 252         kfree(frame);
 253 frame_err:
 254         return NULL;
 255 }
 256
 257 static int process_data(struct sk_buff *skb)
 258 {
 259         u8 iphc0, iphc1;
 260         const struct ieee802154_addr *_saddr, *_daddr;
 261
 262         raw_dump_table(__func__, "raw skb data dump", skb->data, skb->len);
 263         /* at least two bytes will be used for the encoding */
 264         if (skb->len < 2)
 265                 goto drop;
 266
 267         if (lowpan_fetch_skb_u8(skb, &iphc0))
 268                 goto drop;
 269
 270         /* fragments assembling */
 271         switch (iphc0 & LOWPAN_DISPATCH_MASK) {
 272         case LOWPAN_DISPATCH_FRAG1:
 273         case LOWPAN_DISPATCH_FRAGN:
 274         {
 275                 struct lowpan_fragment *frame;
 276                 /* slen stores the rightmost 8 bits of the 11 bits length */
 277                 u8 slen, offset = 0;
 278                 u16 len, tag;
 279                 bool found = false;
 280
 281                 if (lowpan_fetch_skb_u8(skb, &slen) || /* frame length */
 282                     lowpan_fetch_skb_u16(skb, &tag))  /* fragment tag */
 283                         goto drop;
 284
 285                 /* adds the 3 MSB to the 8 LSB to retrieve the 11 bits length */
 286                 len = ((iphc0 & 7) << 8) | slen;
 287
 288                 if ((iphc0 & LOWPAN_DISPATCH_MASK) == LOWPAN_DISPATCH_FRAG1) {
 289                         pr_debug("%s received a FRAG1 packet (tag: %d, "
 290                                  "size of the entire IP packet: %d)",
 291                                  __func__, tag, len);
 292                 } else { /* FRAGN */
 293                         if (lowpan_fetch_skb_u8(skb, &offset))
 294                                 goto unlock_and_drop;
 295                         pr_debug("%s received a FRAGN packet (tag: %d, "
 296                                  "size of the entire IP packet: %d, "
 297                                  "offset: %d)", __func__, tag, len, offset * 8);
 298                 }
 299
 300                 /*
 301                  * check if frame assembling with the same tag is
 302                  * already in progress
 303                  */
 304                 spin_lock_bh(&flist_lock);
 305
 306                 list_for_each_entry(frame, &lowpan_fragments, list)
 307                         if (frame->tag == tag) {
 308                                 found = true;
 309                                 break;
 310                         }
 311
 312                 /* alloc new frame structure */
 313                 if (!found) {
 314                         pr_debug("%s first fragment received for tag %d, "
 315                                  "begin packet reassembly", __func__, tag);
 316                         frame = lowpan_alloc_new_frame(skb, len, tag);
 317                         if (!frame)
 318                                 goto unlock_and_drop;
 319                 }
 320
 321                 /* if payload fits buffer, copy it */
 322                 if (likely((offset * 8 + skb->len) <= frame->length))
 323                         skb_copy_to_linear_data_offset(frame->skb, offset * 8,
 324                                                         skb->data, skb->len);
 325                 else
 326                         goto unlock_and_drop;
 327
 328                 frame->bytes_rcv += skb->len;
 329
 330                 /* frame assembling complete */
 331                 if ((frame->bytes_rcv == frame->length) &&
 332                      frame->timer.expires > jiffies) {
 333                         /* if timer haven't expired - first of all delete it */
 334                         del_timer_sync(&frame->timer);
 335                         list_del(&frame->list);
 336                         spin_unlock_bh(&flist_lock);
 337
 338                         pr_debug("%s successfully reassembled fragment "
 339                                  "(tag %d)", __func__, tag);
 340
 341                         dev_kfree_skb(skb);
 342                         skb = frame->skb;
 343                         kfree(frame);
 344
 345                         if (lowpan_fetch_skb_u8(skb, &iphc0))
 346                                 goto drop;
 347
 348                         break;
 349                 }
 350                 spin_unlock_bh(&flist_lock);
 351
 352                 return kfree_skb(skb), 0;
 353         }
 354         default:
 355                 break;
 356         }
 357
 358         if (lowpan_fetch_skb_u8(skb, &iphc1))
 359                 goto drop;
 360
 361         _saddr = &mac_cb(skb)->sa;
 362         _daddr = &mac_cb(skb)->da;
 363
 364         return lowpan_process_data(skb, skb->dev, (u8 *)_saddr->hwaddr,
 365                                 _saddr->addr_type, IEEE802154_ADDR_LEN,
 366                                 (u8 *)_daddr->hwaddr, _daddr->addr_type,
 367                                 IEEE802154_ADDR_LEN, iphc0, iphc1,
 368                                 lowpan_give_skb_to_devices);
 369
 370 unlock_and_drop:
 371         spin_unlock_bh(&flist_lock);
 372 drop:
 373         kfree_skb(skb);
 374         return -EINVAL;
 375 }
 376
 377 static int lowpan_set_address(struct net_device *dev, void *p)
 378 {
 379         struct sockaddr *sa = p;
 380
 381         if (netif_running(dev))
 382                 return -EBUSY;
 383
 384         /* TODO: validate addr */
 385         memcpy(dev->dev_addr, sa->sa_data, dev->addr_len);
 386
 387         return 0;
 388 }
 389
 390 static int
 391 lowpan_fragment_xmit(struct sk_buff *skb, u8 *head,
 392                         int mlen, int plen, int offset, int type)
 393 {
 394         struct sk_buff *frag;
 395         int hlen;
 396
 397         hlen = (type == LOWPAN_DISPATCH_FRAG1) ?
 398                         LOWPAN_FRAG1_HEAD_SIZE : LOWPAN_FRAGN_HEAD_SIZE;
 399
 400         raw_dump_inline(__func__, "6lowpan fragment header", head, hlen);
 401
 402         frag = netdev_alloc_skb(skb->dev,
 403                                 hlen + mlen + plen + IEEE802154_MFR_SIZE);
 404         if (!frag)
 405                 return -ENOMEM;
 406
 407         frag->priority = skb->priority;
 408
 409         /* copy header, MFR and payload */
 410         skb_put(frag, mlen);
 411         skb_copy_to_linear_data(frag, skb_mac_header(skb), mlen);
 412
 413         skb_put(frag, hlen);
 414         skb_copy_to_linear_data_offset(frag, mlen, head, hlen);
 415
 416         skb_put(frag, plen);
 417         skb_copy_to_linear_data_offset(frag, mlen + hlen,
 418                                        skb_network_header(skb) + offset, plen);
 419
 420         raw_dump_table(__func__, " raw fragment dump", frag->data, frag->len);
 421
 422         return dev_queue_xmit(frag);
 423 }
 424
 425 static int
 426 lowpan_skb_fragmentation(struct sk_buff *skb, struct net_device *dev)
 427 {
 428         int  err, header_length, payload_length, tag, offset = 0;
 429         u8 head[5];
 430
 431         header_length = skb->mac_len;
 432         payload_length = skb->len - header_length;
 433         tag = lowpan_dev_info(dev)->fragment_tag++;
 434
 435         /* first fragment header */
 436         head[0] = LOWPAN_DISPATCH_FRAG1 | ((payload_length >> 8) & 0x7);
 437         head[1] = payload_length & 0xff;
 438         head[2] = tag >> 8;
 439         head[3] = tag & 0xff;
 440
 441         err = lowpan_fragment_xmit(skb, head, header_length, LOWPAN_FRAG_SIZE,
 442                                    0, LOWPAN_DISPATCH_FRAG1);
 443
 444         if (err) {
 445                 pr_debug("%s unable to send FRAG1 packet (tag: %d)",
 446                          __func__, tag);
 447                 goto exit;
 448         }
 449
 450         offset = LOWPAN_FRAG_SIZE;
 451
 452         /* next fragment header */
 453         head[0] &= ~LOWPAN_DISPATCH_FRAG1;
 454         head[0] |= LOWPAN_DISPATCH_FRAGN;
 455
 456         while (payload_length - offset > 0) {
 457                 int len = LOWPAN_FRAG_SIZE;
 458
 459                 head[4] = offset / 8;
 460
 461                 if (payload_length - offset < len)
 462                         len = payload_length - offset;
 463
 464                 err = lowpan_fragment_xmit(skb, head, header_length,
 465                                            len, offset, LOWPAN_DISPATCH_FRAGN);
 466                 if (err) {
 467                         pr_debug("%s unable to send a subsequent FRAGN packet "
 468                                  "(tag: %d, offset: %d", __func__, tag, offset);
 469                         goto exit;
 470                 }
 471
 472                 offset += len;
 473         }
 474
 475 exit:
 476         return err;
 477 }
 478
 479 static netdev_tx_t lowpan_xmit(struct sk_buff *skb, struct net_device *dev)
 480 {
 481         int err = -1;
 482
 483         pr_debug("package xmit\n");
 484
 485         skb->dev = lowpan_dev_info(dev)->real_dev;
 486         if (skb->dev == NULL) {
 487                 pr_debug("ERROR: no real wpan device found\n");
 488                 goto error;
 489         }
 490
 491         /* Send directly if less than the MTU minus the 2 checksum bytes. */
 492         if (skb->len <= IEEE802154_MTU - IEEE802154_MFR_SIZE) {
 493                 err = dev_queue_xmit(skb);
 494                 goto out;
 495         }
 496
 497         pr_debug("frame is too big, fragmentation is needed\n");
 498         err = lowpan_skb_fragmentation(skb, dev);
 499 error:
 500         dev_kfree_skb(skb);
 501 out:
 502         if (err)
 503                 pr_debug("ERROR: xmit failed\n");
 504
 505         return (err < 0) ? NET_XMIT_DROP : err;
 506 }
 507
 508 static struct wpan_phy *lowpan_get_phy(const struct net_device *dev)
 509 {
 510         struct net_device *real_dev = lowpan_dev_info(dev)->real_dev;
 511         return ieee802154_mlme_ops(real_dev)->get_phy(real_dev);
 512 }
 513
 514 static u16 lowpan_get_pan_id(const struct net_device *dev)
 515 {
 516         struct net_device *real_dev = lowpan_dev_info(dev)->real_dev;
 517         return ieee802154_mlme_ops(real_dev)->get_pan_id(real_dev);
 518 }
 519
 520 static u16 lowpan_get_short_addr(const struct net_device *dev)
 521 {
 522         struct net_device *real_dev = lowpan_dev_info(dev)->real_dev;
 523         return ieee802154_mlme_ops(real_dev)->get_short_addr(real_dev);
 524 }
 525
 526 static u8 lowpan_get_dsn(const struct net_device *dev)
 527 {
 528         struct net_device *real_dev = lowpan_dev_info(dev)->real_dev;
 529         return ieee802154_mlme_ops(real_dev)->get_dsn(real_dev);
 530 }
 531
 532 static struct header_ops lowpan_header_ops = {
 533         .create = lowpan_header_create,
 534 };
 535
 536 static const struct net_device_ops lowpan_netdev_ops = {
 537         .ndo_start_xmit         = lowpan_xmit,
 538         .ndo_set_mac_address    = lowpan_set_address,
 539 };
 540
 541 static struct ieee802154_mlme_ops lowpan_mlme = {
 542         .get_pan_id = lowpan_get_pan_id,
 543         .get_phy = lowpan_get_phy,
 544         .get_short_addr = lowpan_get_short_addr,
 545         .get_dsn = lowpan_get_dsn,
 546 };
 547
 548 static void lowpan_setup(struct net_device *dev)
 549 {
 550         dev->addr_len           = IEEE802154_ADDR_LEN;
 551         memset(dev->broadcast, 0xff, IEEE802154_ADDR_LEN);
 552         dev->type               = ARPHRD_IEEE802154;
 553         /* Frame Control + Sequence Number + Address fields + Security Header */
 554         dev->hard_header_len    = 2 + 1 + 20 + 14;
 555         dev->needed_tailroom    = 2; /* FCS */
 556         dev->mtu                = 1281;
 557         dev->tx_queue_len       = 0;
 558         dev->flags              = IFF_BROADCAST | IFF_MULTICAST;
 559         dev->watchdog_timeo     = 0;
 560
 561         dev->netdev_ops         = &lowpan_netdev_ops;
 562         dev->header_ops         = &lowpan_header_ops;
 563         dev->ml_priv            = &lowpan_mlme;
 564         dev->destructor         = free_netdev;
 565 }
 566
 567 static int lowpan_validate(struct nlattr *tb[], struct nlattr *data[])
 568 {
 569         if (tb[IFLA_ADDRESS]) {
 570                 if (nla_len(tb[IFLA_ADDRESS]) != IEEE802154_ADDR_LEN)
 571                         return -EINVAL;
 572         }
 573         return 0;
 574 }
 575
 576 static int lowpan_rcv(struct sk_buff *skb, struct net_device *dev,
 577         struct packet_type *pt, struct net_device *orig_dev)
 578 {
 579         struct sk_buff *local_skb;
 580
 581         if (!netif_running(dev))
 582                 goto drop;
 583
 584         if (dev->type != ARPHRD_IEEE802154)
 585                 goto drop;
 586
 587         /* check that it's our buffer */
 588         if (skb->data[0] == LOWPAN_DISPATCH_IPV6) {
 589                 /* Copy the packet so that the IPv6 header is
 590                  * properly aligned.
 591                  */
 592                 local_skb = skb_copy_expand(skb, NET_SKB_PAD - 1,
 593                                             skb_tailroom(skb), GFP_ATOMIC);
 594                 if (!local_skb)
 595                         goto drop;
 596
 597                 local_skb->protocol = htons(ETH_P_IPV6);
 598                 local_skb->pkt_type = PACKET_HOST;
 599
 600                 /* Pull off the 1-byte of 6lowpan header. */
 601                 skb_pull(local_skb, 1);
 602
 603                 lowpan_give_skb_to_devices(local_skb, NULL);
 604
 605                 kfree_skb(local_skb);
 606                 kfree_skb(skb);
 607         } else {
 608                 switch (skb->data[0] & 0xe0) {
 609                 case LOWPAN_DISPATCH_IPHC:      /* ipv6 datagram */
 610                 case LOWPAN_DISPATCH_FRAG1:     /* first fragment header */
 611                 case LOWPAN_DISPATCH_FRAGN:     /* next fragments headers */
 612                         local_skb = skb_clone(skb, GFP_ATOMIC);
 613                         if (!local_skb)
 614                                 goto drop;
 615                         process_data(local_skb);
 616
 617                         kfree_skb(skb);
 618                         break;
 619                 default:
 620                         break;
 621                 }
 622         }
 623
 624         return NET_RX_SUCCESS;
 625
 626 drop:
 627         kfree_skb(skb);
 628         return NET_RX_DROP;
 629 }
 630
 631 static int lowpan_newlink(struct net *src_net, struct net_device *dev,
 632                           struct nlattr *tb[], struct nlattr *data[])
 633 {
 634         struct net_device *real_dev;
 635         struct lowpan_dev_record *entry;
 636
 637         pr_debug("adding new link\n");
 638
 639         if (!tb[IFLA_LINK])
 640                 return -EINVAL;
 641         /* find and hold real wpan device */
 642         real_dev = dev_get_by_index(src_net, nla_get_u32(tb[IFLA_LINK]));
 643         if (!real_dev)
 644                 return -ENODEV;
 645         if (real_dev->type != ARPHRD_IEEE802154) {
 646                 dev_put(real_dev);
 647                 return -EINVAL;
 648         }
 649
 650         lowpan_dev_info(dev)->real_dev = real_dev;
 651         lowpan_dev_info(dev)->fragment_tag = 0;
 652         mutex_init(&lowpan_dev_info(dev)->dev_list_mtx);
 653
 654         entry = kzalloc(sizeof(struct lowpan_dev_record), GFP_KERNEL);
 655         if (!entry) {
 656                 dev_put(real_dev);
 657                 lowpan_dev_info(dev)->real_dev = NULL;
 658                 return -ENOMEM;
 659         }
 660
 661         entry->ldev = dev;
 662
 663         /* Set the lowpan harware address to the wpan hardware address. */
 664         memcpy(dev->dev_addr, real_dev->dev_addr, IEEE802154_ADDR_LEN);
 665
 666         mutex_lock(&lowpan_dev_info(dev)->dev_list_mtx);
 667         INIT_LIST_HEAD(&entry->list);
 668         list_add_tail(&entry->list, &lowpan_devices);
 669         mutex_unlock(&lowpan_dev_info(dev)->dev_list_mtx);
 670
 671         register_netdevice(dev);
 672
 673         return 0;
 674 }
 675
 676 static void lowpan_dellink(struct net_device *dev, struct list_head *head)
 677 {
 678         struct lowpan_dev_info *lowpan_dev = lowpan_dev_info(dev);
 679         struct net_device *real_dev = lowpan_dev->real_dev;
 680         struct lowpan_dev_record *entry, *tmp;
 681
 682         ASSERT_RTNL();
 683
 684         mutex_lock(&lowpan_dev_info(dev)->dev_list_mtx);
 685         list_for_each_entry_safe(entry, tmp, &lowpan_devices, list) {
 686                 if (entry->ldev == dev) {
 687                         list_del(&entry->list);
 688                         kfree(entry);
 689                 }
 690         }
 691         mutex_unlock(&lowpan_dev_info(dev)->dev_list_mtx);
 692
 693         mutex_destroy(&lowpan_dev_info(dev)->dev_list_mtx);
 694
 695         unregister_netdevice_queue(dev, head);
 696
 697         dev_put(real_dev);
 698 }
 699
 700 static struct rtnl_link_ops lowpan_link_ops __read_mostly = {
 701         .kind           = "lowpan",
 702         .priv_size      = sizeof(struct lowpan_dev_info),
 703         .setup          = lowpan_setup,
 704         .newlink        = lowpan_newlink,
 705         .dellink        = lowpan_dellink,
 706         .validate       = lowpan_validate,
 707 };
 708
 709 static inline int __init lowpan_netlink_init(void)
 710 {
 711         return rtnl_link_register(&lowpan_link_ops);
 712 }
 713
 714 static inline void lowpan_netlink_fini(void)
 715 {
 716         rtnl_link_unregister(&lowpan_link_ops);
 717 }
 718
 719 static int lowpan_device_event(struct notifier_block *unused,
 720                                unsigned long event, void *ptr)
 721 {
 722         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
 723         LIST_HEAD(del_list);
 724         struct lowpan_dev_record *entry, *tmp;
 725
 726         if (dev->type != ARPHRD_IEEE802154)
 727                 goto out;
 728
 729         if (event == NETDEV_UNREGISTER) {
 730                 list_for_each_entry_safe(entry, tmp, &lowpan_devices, list) {
 731                         if (lowpan_dev_info(entry->ldev)->real_dev == dev)
 732                                 lowpan_dellink(entry->ldev, &del_list);
 733                 }
 734
 735                 unregister_netdevice_many(&del_list);
 736         }
 737
 738 out:
 739         return NOTIFY_DONE;
 740 }
 741
 742 static struct notifier_block lowpan_dev_notifier = {
 743         .notifier_call = lowpan_device_event,
 744 };
 745
 746 static struct packet_type lowpan_packet_type = {
 747         .type = __constant_htons(ETH_P_IEEE802154),
 748         .func = lowpan_rcv,
 749 };
 750
 751 static int __init lowpan_init_module(void)
 752 {
 753         int err = 0;
 754
 755         err = lowpan_netlink_init();
 756         if (err < 0)
 757                 goto out;
 758
 759         dev_add_pack(&lowpan_packet_type);
 760
 761         err = register_netdevice_notifier(&lowpan_dev_notifier);
 762         if (err < 0) {
 763                 dev_remove_pack(&lowpan_packet_type);
 764                 lowpan_netlink_fini();
 765         }
 766 out:
 767         return err;
 768 }
 769
 770 static void __exit lowpan_cleanup_module(void)
 771 {
 772         struct lowpan_fragment *frame, *tframe;
 773
 774         lowpan_netlink_fini();
 775
 776         dev_remove_pack(&lowpan_packet_type);
 777
 778         unregister_netdevice_notifier(&lowpan_dev_notifier);
 779
 780         /* Now 6lowpan packet_type is removed, so no new fragments are
 781          * expected on RX, therefore that's the time to clean incomplete
 782          * fragments.
 783          */
 784         spin_lock_bh(&flist_lock);
 785         list_for_each_entry_safe(frame, tframe, &lowpan_fragments, list) {
 786                 del_timer_sync(&frame->timer);
 787                 list_del(&frame->list);
 788                 dev_kfree_skb(frame->skb);
 789                 kfree(frame);
 790         }
 791         spin_unlock_bh(&flist_lock);
 792 }
 793
 794 module_init(lowpan_init_module);
 795 module_exit(lowpan_cleanup_module);
 796 MODULE_LICENSE("GPL");
 797 MODULE_ALIAS_RTNL_LINK("lowpan");